CN101158167A - Backhoe hydraulic system - Google Patents
Backhoe hydraulic system Download PDFInfo
- Publication number
- CN101158167A CN101158167A CNA2007101532299A CN200710153229A CN101158167A CN 101158167 A CN101158167 A CN 101158167A CN A2007101532299 A CNA2007101532299 A CN A2007101532299A CN 200710153229 A CN200710153229 A CN 200710153229A CN 101158167 A CN101158167 A CN 101158167A
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- mentioned
- valve
- control valve
- flow channel
- channel switching
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2221—Control of flow rate; Load sensing arrangements
- E02F9/2239—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2278—Hydraulic circuits
- E02F9/2292—Systems with two or more pumps
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2278—Hydraulic circuits
- E02F9/2296—Systems with a variable displacement pump
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
- F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
- F15B11/165—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for adjusting the pump output or bypass in response to demand
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
- F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/20576—Systems with pumps with multiple pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/305—Directional control characterised by the type of valves
- F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
- F15B2211/3053—In combination with a pressure compensating valve
- F15B2211/30555—Inlet and outlet of the pressure compensating valve being connected to the directional control valve
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/31—Directional control characterised by the positions of the valve element
- F15B2211/3105—Neutral or centre positions
- F15B2211/3116—Neutral or centre positions the pump port being open in the centre position, e.g. so-called open centre
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/32—Directional control characterised by the type of actuation
- F15B2211/329—Directional control characterised by the type of actuation actuated by fluid pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7051—Linear output members
- F15B2211/7053—Double-acting output members
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7058—Rotary output members
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- Operation Control Of Excavators (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
The present invention overcomes drawbacks whereby the supply of pressure oil to a hydraulic cylinder for operating a ground working device is temporarily cut, and operation of the ground working device is temporarily stopped when a control valve for the travel device is operated while a control valve for the ground working device is being operated. When control valves (V4, V5) for the travel devices are operated during operation of control valves (V6, V7, V8) for the ground working device, and a first flow channel switching valve (V12) is switched from an operating position (31) to a travel position (34), a second flow channel switching valve (V13) is switched from a non-feeding position (39) to a feeding position (40) before or at the same time as the first flow channel switching valve (V12).
Description
Technical field
The present invention relates to be equipped with the hydraulic system that the panoramic table of apparatus for work over the ground can carry the excavator on the body of advancing freely to rotate around the axle center of above-below direction.
Background technology
In the prior art, can carry the hydraulic system that has by the excavator on the body of advancing of hydraulically powered pair of right and left moving device freely to rotate around the axle center of above-below direction as being equipped with by the panoramic table of hydraulically powered apparatus for work over the ground, when non-advancing, make from the pressure oil of the 1st pump and the 2nd pump interflow and offer apparatus for work over the ground, and will offer from the pressure oil of the 3rd pump and make the rotating rotary motor of panoramic table, when advancing, a side moving device and left and right sides the opposing party's moving device about will offering independently respectively from the pressure oil of the 1st pump with from the pressure oil of the 2nd pump, and will offer the hydraulic actuator of apparatus for work (for example with reference to Japanese 2006-161510A) over the ground from the pressure oil of the 3rd pump.
In this hydraulic system, have: the 1st flow channel switching valve, can between job position and advanced positions, switch, described job position is the position that makes from the pressure oil of the 1st pump and the 2nd pump interflow and offer the control valve that apparatus for work over the ground uses, and described advanced positions is the position of the control valve used of the moving device about the pressure oil from the 1st pump and the 2nd pump is offered respectively independently; With the 2nd flow channel switching valve, can and supply with between the position in non-supply position and switch, described non-supply position is the position that will not offer the control valve that apparatus for work over the ground uses from the pressure oil of the 3rd pump, and described supply position is the position that the pressure oil from the 3rd pump is offered the control valve that apparatus for work over the ground uses.
In addition, in above-mentioned hydraulic system, the 2nd flow channel switching valve and the 1st flow channel switching valve are made of the pilot operated transfer valve that carries out handover operation by pilot pressure, when detecting the control valve that moving device is used and carried out operation, pilot pressure is delivered to advance valve and flow channel switching valve both sides, and when detecting the control valve that apparatus for work is over the ground used and carried out operation, pilot pressure is delivered to flow channel switching valve.
In addition, the 1st flow channel switching valve constitutes by operating the pilot pressure that produces by means of the control valve that moving device is used and switches to advanced positions from job position, the 2nd flow channel switching valve constitutes, when non-advancing, do not supply with the position and remain on non-supply position because of the pilot pressure of operating generation by means of the control valve that apparatus for work is over the ground used switches to, when using over the ground apparatus for work and the control valve that moving device is used carried out operation, supply with the position by operating the pilot pressure that produces by means of the control valve that apparatus for work is over the ground used and switching to by means of the pilot pressure sum that the control valve that moving device is used is operated the pilot pressure that produces.
In above-mentioned hydraulic system, in using the process of apparatus for work over the ground, the control valve that moving device is used has carried out under the situation of operation, when the 1st flow channel switching valve during than the first switching of the 2nd flow channel switching valve, for example in promoting the course of work of swing arm, carried out advancing under the situation of operation, in case interrupt pressure oil supply, the unfavorable condition that swing arm work temporarily stops can to take place to the swing arm cylinder that makes swing arm work.
Summary of the invention
Therefore, the objective of the invention is to solve when the control valve that apparatus for work is over the ground used is operated, when the control valve that moving device is used has carried out operation, in case interrupt the pressure oil of the hydraulic cylinder of apparatus for work work is supplied with, over the ground the unfavorable condition that temporarily stops of the work of apparatus for work.
The feature formation of the hydraulic system of excavator of the present invention is to have: advance and use pump, pressure oil is offered the control valve that moving device is used; Pump is used in revolution, and pressure oil is offered the control valve that panoramic table is used; The 1st flow channel switching valve, can between job position and advanced positions, switch, described job position is will enter the position that pressure oil with pump offers the control valve that apparatus for work over the ground uses from above line when non-advancing, and described advanced positions is the position of the control valve used of the moving device about will advancing pressure oil with pump and offer from above line when advancing; The 2nd flow channel switching valve, can and supply with between the position in non-supply position and switch, described non-supply position is will not offer the position of the control valve that above-mentioned apparatus for work over the ground uses from above-mentioned revolution with the pressure oil of pump, described supply position is to offer the position of the control valve that apparatus for work over the ground uses with the pressure oil of pump from above-mentioned revolution, in the process of operating at the control valve that above-mentioned apparatus for work is over the ground used, the control valve that the above line motion device is used is operated, make above-mentioned the 1st flow channel switching valve when job position switches to advanced positions, above-mentioned the 2nd flow channel switching valve and above-mentioned the 1st flow channel switching valve switch to from non-supply position earlier simultaneously or than above-mentioned the 1st flow channel switching valve and supply with the position.
As this formation, in the process of operating at the control valve that apparatus for work is over the ground used, when the control valve that moving device is used had carried out operation, the 2nd flow channel switching valve constituted and the 1st flow channel switching valve switches earlier simultaneously or than the 1st flow channel switching valve, thus.For example in promoting the course of work of swing arm, carried out advancing under the situation of operation, in case interrupt the supply of pressure oil to the swing arm cylinder that makes swing arm work, the unfavorable condition that swing arm work was once stopping can not to appear, in the process of using apparatus for work over the ground, when the control valve that moving device is used has carried out operation, can guarantee the continuity of the motion of apparatus for work over the ground.
Moreover, preferably, above-mentioned advancing has the 1st pump and these two pumps of the 2nd pump with pump, above-mentioned the 1st flow channel switching valve constitutes, above-mentioned job position make from the pressure oil of above-mentioned the 1st pump with from the pressure oil interflow of above-mentioned the 2nd pump and offer the control valve that above-mentioned apparatus for work is over the ground used, and the control valve that the moving device about offering independently of one another from the pressure oil of above-mentioned the 1st pump and pressure oil from above-mentioned the 2nd pump is used in above-mentioned advanced positions.
Moreover, the hydraulic system of this excavator also can constitute to be had: advance and detect the loop, when the control valve that the above line motion device is used had carried out operation, this detection loop of advancing offered above-mentioned the 1st flow channel switching valve so that the 1st flow channel switching valve is switched to above-mentioned advanced positions with pilot pressure; With the stream switching circuit, in the process of operating at the control valve that above-mentioned apparatus for work is over the ground used, when the control valve that the above line motion device is used has carried out operation, this stream switching circuit can offer pilot pressure the 2nd flow channel switching valve, so that being switched to, the 2nd flow channel switching valve supplies with the position, above-mentioned stream switching circuit is provided with stream switch operating valve, this stream switch operating valve constitutes, can and pilot pressure be offered between the operating position of above-mentioned the 2nd flow channel switching valve at the off-position that pilot pressure is not offered above-mentioned the 2nd flow channel switching valve and freely switch, and by switching to the operating position from the above-mentioned pilot pressure that detects the loop of advancing.
The stream switch operating valve that is installed on this stream switching circuit also can be set, this stream switch operating valve constitutes, can and pilot pressure be offered between the operating position of flow channel switching valve at the off-position that pilot pressure is not offered flow channel switching valve and freely switch, and by switching to the operating position from the pilot pressure that detects the loop of advancing.
By such formation, can easily set the switch pressure of stream switch operating valve, so that the pilot pressure of stream switch operating valve by the pressure identical with the 1st transfer valve switches to the operating position, perhaps make the pilot pressure of the pressure of stream switch operating valve by being lower than the 1st transfer valve switch to the operating position, can easily constitute hydraulic system, in the process of using apparatus for work over the ground, when the control valve that moving device is used had carried out operation, flow channel switching valve and the valve of advancing were simultaneously or than the valve switching earlier of advancing.
Description of drawings
Fig. 1 is the unitary side view of excavator.
Fig. 2 is whole hydraulic circuit diagram.
Fig. 3 is the hydraulic circuit diagram of the work system of the 1st flow channel switching valve and the 2nd flow channel switching valve.
Fig. 4 is the hydraulic circuit diagram of automatic speed reducing system of advancing.
Fig. 5 is the hydraulic circuit diagram of revolution automatic speed reducing system.
Label declaration
31: job position
34: advanced positions
39: non-supply position
40: supply with the position
41: the stream switching circuit
54: advance and detect the loop
58: off-position
59: the operating position
P1: the 1st pump
P2: the 2nd pump
P3: the 3rd pump
V1: revolution control valve
V4: advance and use control valve in the left side
V5: advance and use control valve in the right side
V6: big arm control valve
V7: scraper bowl control valve
V8: swing arm control valve
V12: the 1st flow channel switching valve
V13: the 2nd flow channel switching valve
V17: stream switch operating valve
The specific embodiment
Embodiments of the present invention are described with reference to the accompanying drawings.In Fig. 1, the 1st, excavator, this excavator 1 are mainly by the body 2 and constituting around the revolving body 3 that the mode of the revolution axle center full circle swinging of above-below direction is carried on this advances body 2 of advancing of bottom.
The body 2 of advancing has crawler-tread 7 in the left and right sides of track frame 4, and the motor 5 of advancing that this crawler-tread 7 constitutes by being made of hydraulic motor makes crawler belt 6 shuttling movements.
Be provided with bulldozer device 8 in the front portion of above-mentioned track frame 4.The spatula of this bulldozer device promotes/down maneuver by the flexible of bulldozer cylinder 9 that is made of hydraulic cylinder.
Revolving body 3 has in the mode of can the wraparound rotating shaft heart freely rotating and carries at the panoramic table on the track frame 4 10, is equipped in the apparatus for work over the ground (digging operation device) 11 of the front portion of panoramic table 10 and carries driver's cabin 12 on panoramic table 10.
Panoramic table 10 is provided with motor, radiator, fuel tank, operating oil tank and power supply etc., and this panoramic table 10 drives revolution by the rotary motor 13 that is made of hydraulic motor.
In addition, be provided with rocking bracket 15 in the front portion of panoramic table 10, this rocking bracket 15 can be around the left and right sides, axle center of above-below direction free swaying ground supporting from this panoramic table 10 frame support bracket 14 that forwards standing shape ground is provided with, the operation that swings of the flexible quilt of this rocking bracket 15 by the oscillating cylinder 16 that is made of hydraulic cylinder.
Apparatus for work 11 is mainly by constituting with lower member over the ground: swing arm 17, base portion side can around Y-axis freely to rotate pivot prop up the top that is connected rocking bracket 15 and can the easy on and off swing; Big arm 18, base portion side can around Y-axis freely to rotate pivot prop up the front that is connected this swing arm 17 and can before and after freely swing; With scraper bowl 19, can around Y-axis freely to rotate pivot prop up the front that is connected this big arm 18 and can before and after freely swing.
Above-mentioned swing arm cylinder 21, big arm cylinder 22 and scraper bowl cylinder 23 are made of hydraulic cylinder respectively.
Next be used to make the hydraulic system that is equipped in the various hydraulic actuator work on the above-mentioned excavator 1 with reference to Fig. 2～Fig. 4 explanation.
In Fig. 2, V1 is the revolution control valve of control rotary motor 13, V2 is the bulldozer control valve of control bulldozer cylinder 9, V3 is the swing control valve of control oscillating cylinder 16, V4 is to advance and use control valve in the left side of the travel motor 5 in control left side, V5 is to advance and use control valve in the right side of travel motor 5 on control right side, V6 is the big arm control valve of the big arm cylinder 22 of control, V7 is the scraper bowl control valve of control scraper bowl cylinder 23, V8 is the swing arm control valve of control swing arm cylinder 21, and V9 controls the SP control valve that is installed in the hydraulic fittings such as hydraulic breaker on the apparatus for work 11 over the ground in addition.
These control valves V1～9 are made of straight movable pulley shape transfer valve, and constitute by the pilot operated transfer valve that is carried out handover operation by pilot pressure.Each control valve V1～9 constitutes with operational ton to this control valve V1～9 each operating mechanism of operating and moves with being directly proportional, thereby will offer the hydraulic actuator of control object with the pressure oil of each control valve V1～amount that 9 amounts of being moved are directly proportional, and make the operating rate of operand to change with being directly proportional with the operational ton of each operating mechanism.
Advance and carry out handover operation with pilot valve PV1 in the advance left side of operating with the travel rod 24 of control valve V4 by the quilt left side, left side, advance and carry out handover operation by being advanced by the right side of travel rod 25 operations on right side with pilot valve PV2 with control valve V5 in the right side, these travel rod 24,25 and pilot valve PV1, PV2 are configured in the driver's seat front side in the driver's cabin 12.
About travel rod 24,25 be set to the operation of can on fore-and-aft direction, fascinating, to about advance and operate with control valve V4, V5, with box lunch should about travel rod 24,25 when inclination is fallen forward so that the mode of corresponding moving device 7 forward drive drives travel motor 5, and when about travel rod 24,25 drive travel motor 5 so that the moving device 7 of correspondence retreats the mode of driving when inclination is fallen backward.
Revolution is carried out handover operation by the manipulation of being operated by a control stick 26 with pilot valve PV3 with control valve V6 with control valve V1 and big arm, and this control stick 26 is configured in the left side of driver's seat.
In addition, scraper bowl also carries out handover operation by the manipulation of being operated by a control stick 27 with pilot valve PV4 with control valve V7 and swing arm with control valve V8, and this control stick 27 is configured in the right side of driver's seat.
About control stick 26,27 are set to respectively the operation of fascinating about can be forwards, backwards, in the present embodiment, to pairing each control valve V1, V6 operates, panoramic table about 10 revolutions when toppling over to the left and right with the control stick 26 in box lunch left side, big arm 18 dumps/loads action when the control stick 26 in left side is toppled over forwards, backwards, and to pairing each control valve V7, V8 operates, scraper bowl 19 loads/dumps work when toppling over to the left and right with the control stick 27 on convenient right side, and swing arm 17 promotes/down maneuver when the control stick 27 on right side is toppled over forwards, backwards.
Bulldozer is operated by the pilot valve that has been omitted illustrated operating mechanism operation respectively with control valve V9 with control valve V3 and SP with control valve V2, swing.
The pump as the pressure oil supply source in this hydraulic system has the 1st pump P1, the 2nd pump P2, the 3rd pump P3 and the 4th pump P4, and these pumps P1, P2, P3, P4 are driven by the motor E that carries on panoramic table 10.
The 1st pump P1 and the 2nd pump P2 are oblique disc variable capacity axial pumps, and by obtain to equate that the flow double pump that waits of discharge rates forms as one from 2 outlet openings, these the 1st pump P1 and the 2nd pump P2 conduct are advanced and be mainly used in travel motor 5 with pump.Be used for the hydraulic cylinder of apparatus for work 11 over the ground in addition.
The 3rd pump P3 and the 4th pump P4 constitute by the gear pump of constant volume shape.The 3rd pump P3 is mainly used in rotary motor 13 as revolution with pump.In addition, the 3rd pump P3 also is used for bulldozer cylinder 9 and oscillating cylinder 16.The 4th pump P4 is used to provide pilot pressure.
In addition, the 1st pump P1 and the 2nd pump P2 also can distinguish formation separately.
In this hydraulic system, adopt the load sensing system, this load sensing system controls the discharge rate of the 1st, 2 pump P1, P2 corresponding to the working load pressure of swing arm 17, big arm 18 and scraper bowl 19 etc., discharge the required hydraulic power of load from the 1st, 2 pump P1, P2, can save power thus and improve operability, this load sensing system adopts the back pinhole type that is connected with pressure-compensated valve CV at big arm with control valve V6, scraper bowl with control valve V7, swing arm with control valve V8 and SP after with the main slide valve of control valve V9 respectively.
Diagram is omitted in the control system loop of this load sensing system.
In the drawings, V10 is the unloader in the load sensing system, and V11 is the security of system valve in the load sensing system.
Moreover, advance, the each several part of revolution, bulldozer and swing is made of open circuit.
In this hydraulic system, when non-advancing, can make from the pressure oil of the 1st pump P1 and the 2nd pump P2 interflow and offer each control valve V8, V6, V7, the V9 that swing arm 17, big arm 18, scraper bowl 19 and SP use, when advancing, can be with control valve V4, the V5 of moving device 7 usefulness about offering independently respectively from the pressure oil of the 1st pump P1 with from the pressure oil of the 2nd pump P2, and will offer each control valve V8, V6, V7, the V9 that swing arm 17, big arm 18, scraper bowl 19 and SP use from the pressure oil of the 3rd pump P3.
Illustrate that with reference to Fig. 2 and Fig. 3 the hydraulic circuit that this work is carried out constitutes.
On the discharge loop 28,29 of the 1st pump P1 and the 2nd pump P2, be connected with the 1st flow channel switching valve V12 by the pilot operated transfer valve formation of straight movable pulley shape.
The 1st flow channel switching valve V12 can freely switch between job position 31 and advanced positions 34, described job position 31 be make the discharge loop 28 of the 1st pump P1 and the 2nd pump P2 29 interflow, discharge loop and with pressure oil is offered swing arm 17, big arm 18, each control valve V8 that scraper bowl 19 and SP use, V6, V7, the position that the operating system supply circuit 30 of V9 connects, described advanced positions 34 is to make the discharge loop 28 of the 1st pump P1 and pressure oil is offered the right side and advance and be connected and make the discharge loop 29 of the 2nd pump P2 and pressure oil is offered the position of advancing and being connected with the left supply circuit 33 of advancing of control valve V4, left side with the right supply circuit 32 of advancing of control valve V5, the 1st flow channel switching valve V12 switches to job position 31 by spring, switches to advanced positions 34 by the pilot pressure that produces on the switching circuit 35 of advancing.
On the discharge loop 36 of the 3rd pump P3, be connected with pressure oil offer revolution with, bulldozer with and each control valve V1, V2 of swing usefulness, the pressure oil feed path 37 of V3, and should discharge loop 36 and be connected with the 2nd flow channel switching valve V13 with control valve V3 with control valve V2, swing with control valve V1, bulldozer by revolution successively.
In addition, at the upstream side of the 2nd flow channel switching valve V13 in the discharge loop 36 of the 3rd pump P3 and to be swing be connected with link circuit 38 with the position in the downstream of control valve V3, this link circuit 38 is connected with above-mentioned operating system supply circuit 30, the discharge loop 36 of the 3rd pump P3 is connected by link circuit 38 with operating system supply circuit 30, clamped one way valve V14 on this link circuit 38, this one way valve V14 stops the discharge loop side flow of pressure oil from operating system supply circuit 30 side direction the 3rd pump P3.
Above-mentioned the 2nd flow channel switching valve V13 is made of the pilot operated transfer valve of straight movable pulley shape, can and supply with between the position 40 in non-supply position 39 and freely switch, described non-supply position 39 is that the discharge loop 36 by making the 3rd pump P3 is connected with discharging loop d and will offer operating system supply circuit 30 (swing arm 17 from the pressure oil of the 3rd pump P3, big arm 18, each control valve V8 that scraper bowl 19 and SP use, V6, V7, V9) position, described supply position 40 is will offer the position of operating system supply circuit 30 by the discharge loop 36 that cuts off the 3rd pump P3 from the discharge oil of the 3rd pump P3 via link circuit 38 with being communicated with of loop d of discharging, above-mentioned the 2nd flow channel switching valve V13 switches to non-supply position 39 by spring, switches to by the pilot pressure that produces on stream switching circuit 41 and supplies with position 40.
Shunt by the 1st～3 discharge loop 42,43,44 from the pressure oil that the 4th pump P4 discharges, the 1st discharges loop 42 is connected with unloader V15, the 2nd discharges loop 43 is connected with the two fast transfer valve V16 that advance, and the 3rd discharges loop 44 branches into valve operation detection loop the 45, the 1st pilot pressure supply circuit 46 and the 2nd pilot pressure supply circuit 47.
Unloader V15 is made of electromagnetic valve, can between supply position 48 and non-supply position 49, freely switch, described supply position 48 be with offer from the above-mentioned the 1st pressure oil of discharging loop 42 to about advance and use pilot valve PV1, PV2, about manipulation pilot valve PV3, PV4, the pilot valve that bulldozer is operated with control valve V2 (omitting diagram), to swinging the pilot valve of operating with control valve V3 (omitting diagram), position with the pilot valve that SP is operated with control valve V9 (omitting diagram), described non-supply position 49 is to discharge the pressure oil in loop 42 from the above-mentioned the 1st and pressure oil is not offered the position of these pilot valves by discharging, unloader V15 switches to non-supply position 49 by spring, switches to by excitation signal and supplies with position 48.
Lifting/step-down operation to excitation/erase signal of unloader V15 securing rod by being configured in the driver's seat side is sent, when when excavator 1 is got off, by lifting securing rod unloader V15 is sent erase signal, this unloader V15 is switched to non-supply position 49, after taking excavator 1, send excitation signal by depressing securing rod, unloader V15 is switched to supplying with position 48.
The two fast transfer valve V16 that advance will be described hereinafter.
Valve operation detection loop 45 constitutes, advance to advance with control valve V3 → left side with control valve V2 → swing with control valve V1 → bulldozer through throttle orifice 50 → revolution and use control valve V9 and discharge loop d and be connected with the arm control valve V6 → scraper bowl control valve V7 → swing arm control valve V8 → SP of control valve V5 → greatly with control valve V4 → right side, between the throttle orifice 50 in this valve operation detection loop 45 and revolution are with control valve V1, be connected with the A1 switch 51 that constitutes by pressure switch, by some in above-mentioned control valve V1～9 operated from the neutral position, the part in stop valve operation detection loop 45, produce pressure on this valve operation detection loop 45, this pressure detects by A1 switch 51.
When not detecting pressure by above-mentioned A1 switch 51, the rotating speed of motor E is reduced to idle running automatically, and when detecting pressure by A1 switch 51, the rotating speed of motor E increases to set rotating speed automatically, like this rotating speed of automatically controlled engine E.
The 1st pilot pressure supply circuit 46 is connected with the switching circuit 35 of advancing with valve operation circuit 52, has clamped throttle orifice 53 at the upstream side of the valve operation circuit 52 of the 1st pilot pressure supply circuit 46 and the tie point a of the switching circuit 35 of advancing.
Moreover being connected with on the switching circuit 35 of advancing advances detects loop 54, this advance detect loop 54 through the left side advance with control valve V4 → right side advance with control valve V5 with discharge loop d and be connected.
The 2nd pilot pressure supply circuit 47 and the right side in valve operation detection loop 45 are advanced with the downstream of control valve V5 and to be big arm be connected with the upstream side of control valve V6, clamps throttle orifice 55 successively and stops pressure oil from the logical one way valve 56 of valve operation detection loop 45 side direction throttle orifices, 55 effluents from upstream side on the 2nd pilot pressure supply circuit 47.
Between the throttle orifice 55 of the 2nd pilot pressure supply circuit 47 and one way valve 56, be connected with above-mentioned stream switching circuit 41, on this stream switching circuit 41, clamp the stream switch operating valve V17 that constitutes by the pilot operated transfer valve of straight movable pulley shape, be connected with above-mentioned valve operation circuit 52 in the spool valve end (pilot port) of this stream switch operating valve V17.
This stream switch operating valve V17 can freely switch between off-position 58 and operating position 59, described off-position 58 is to flow to the position of discharging loop d and pilot pressure not offered the 2nd flow channel switching valve V13 by the pressure oil that makes the stream switching circuit 41 of flowing through, described operating position 59 is the positions that the pilot pressure of the stream switching circuit 41 of flowing through offered the 2nd flow channel switching valve V13, this stream switch operating valve V17 switches to off-position 58 by spring, and switches to operating position 59 by the pilot pressure that produces on valve operation circuit 52.
In the above-described configuration, not to about advance and use control valve V4, under the situation that V5 operates (about advance and use control valve V4, V5 is positioned under the situation of neutral position), because in the detection loop 54 of advancing, advance and do not produce pressure on switching circuit 35 and the valve operation circuit 52, so the 1st flow channel switching valve V12 is in job position 31 and stream switch operating valve V17 is in off-position 58, the 2nd flow channel switching valve V13 is in non-supply position, from the discharge oil interflow of the 1st pump and the 2nd pump, and pressure oil can be offered big arm 18, scraper bowl 19, each control valve V6 that swing arm 17 and SP use, V7, V8, V9.
When under this state to big arm 18, scraper bowl 19, each control valve V6 that swing arm 17 and SP use, V7, V8, when V9 operates from the neutral position, valve operation detection loop 45 is cut off in the downstream of the tie point b of valve operation detection loop 45 and the 2nd pilot pressure supply circuit 47, though the pressure oil from the 2nd pilot pressure supply circuit 47 flow to stream switching circuit 41, but because stream switch operating valve V17 is positioned at off-position 58, the pressure oil of stream switching circuit 41 flow to discharging loop d so flow through, spool valve end at the 2nd flow channel switching valve V13 can not produce pilot pressure, the 2nd flow channel switching valve V13 remains on non-supply position 39, does not offer big arm 18 from the pressure oil of the 3rd pump P3, scraper bowl 19, each control valve V6 that swing arm 17 and SP use, V7, V8, V9.
On the other hand, to about advance when operating from the neutral position with control valve V4, V5, the part that detects loop 54 of advancing is cut off, on advancing detection loop 54, advance switching circuit 35 and valve operation circuit 52, this produces pressure, the 1st flow channel switching valve V12 switches to advanced positions 34, and stream switch operating valve V17 switches to operating position 59.
Thus, offer the right side from the discharge oil of the 1st pump P1 and advance with control valve V5 and offer the left side and advance and use control valve V4, do not offer the control valve that big arm 18, scraper bowl 19, swing arm 17 and SP use from the discharge oil of the 1st, 2 pump P1, P2 from the discharge oil of the 2nd pump P2.
At this moment, when not to big arm 18, scraper bowl 19, the control valve V6 that swing arm 17 and SP use, V7, V8, when V9 operates, even stream switch operating valve V17 switches to operating position 59, pressure oil from the 2nd pilot pressure supply circuit 47 also flow to discharging loop d through one way valve 56 → valve operation detection loop 45, though do not supply with position 40 (remaining on non-supply position 39) so the 2nd flow channel switching valve V13 switches to, if but to big arm 18, scraper bowl 19, the control valve V6 that swing arm 17 and SP use, V7, V8, V9 operates and during stop valve operation detection loop 45, because stream switch operating valve V17 switches to operating position 59, so on stream switching circuit 41, produce pressure, by this pressure the 2nd flow channel switching valve V13 is switched to and supply with position 40, and the pressure oil from the 3rd pump can be offered big arm 18, scraper bowl 19, each control valve V6 that swing arm 17 and SP use, V7, V8, V9.
In addition, under the state that control valve V6, V7, V8, V9 that big arm 18, scraper bowl 19, swing arm 17 and SP are used operate, for example promoting under the state of operation with control valve V8 to swing arm, to advancing with under one or two situation of operating among control valve V4, the V5, flow at the pressure oil from the 2nd pilot pressure supply circuit 47 under the state of stream switching circuit 41, the 1st flow channel switching valve V12 switches to advanced positions 34 and stream switch operating valve V17 switches to operating position 59.Moreover, because stream switch operating valve V17 switches to operating position 59,, the 2nd flow channel switching valve V13 supplies with position 40 so switching to.Thus, break off providing pressure oil to swing arm with control valve V8, offer swing arm control valve V8, so the work of swing arm 17 continues from the pressure oil of the 3rd pump P3 from the 1st, 2 pump P1, P2.
At this moment, as the 1st flow channel switching valve V12 during than early switching of stream switch operating valve V17, the temporary transient interruption supplied with the pressure oil of control valve V8 swing arm, the motion of swing arm 17 once stopped, therefore, in the present embodiment, the switch pressure of the 1st flow channel switching valve V12 and stream switch operating valve V17 is set at, stream switch operating valve V17 switches to operating position 59 by the pilot pressure of the pressure identical with the 1st flow channel switching valve V12, and perhaps stream switch operating valve V17 is by switching to operating position 59 than the low pilot pressure of the 1st flow channel switching valve V12.
Thus, under the state that swing arm is promoted operation with control valve V8 to the situation of operating of advancing with control valve V4, V5 under, the work of swing arm 17 can once not interrupted, and has kept the continuity of the lifting action of swing arm 17.
In addition, under the state that swing arm is carried out step-down operation with control valve V8 or under control valve V6, V7 that big arm 18, scraper bowl 19 and SP are used, state that V9 operates, identical with the situation of operating with control valve V4, V5 to advancing.
Moreover, in existing hydraulic system, when in the process that makes apparatus for work work over the ground, moving device being operated, the switch pressure of the 2nd flow channel switching valve and the 2nd flow channel switching valve to be adjusted to, the 2nd flow channel switching valve is with the 2nd flow channel switching valve while or than under the first situation about switching of the 2nd flow channel switching valve, if the switch pressure of the 2nd flow channel switching valve is low excessively, under the situation that makes apparatus for work work over the ground, the 2nd flow channel switching valve switches to the problem of supplying with the position though the control valve that might occur moving device not being used is for various reasons operated, and the switch pressure of the 2nd flow channel switching valve can not be low excessively.Moreover, if the switch pressure of the 2nd flow channel switching valve is unnecessarily high, then there is the situation that can produce problems such as response, in existing hydraulic system, being difficult to be set at reliably the 2nd flow channel switching valve switches earlier simultaneously or than the 2nd flow channel switching valve with the 2nd flow channel switching valve, exist when the control valve of when using apparatus for work over the ground moving device being used has carried out operation, the 2nd flow channel switching valve is than the problem of the first switching of the 2nd flow channel switching valve.
Be directed to this, in the hydraulic system of above-mentioned formation, can easily set the switch pressure of stream switch operating valve V17, so that the pilot pressure of stream switch operating valve V17 by the pressure identical with the 1st flow channel switching valve V12 switches to operating position 59, perhaps make stream switch operating valve V17 switch to operating position 59 by the pilot pressure that is lower than the 1st flow channel switching valve V12, can easily constitute hydraulic system, and make when in using the process of apparatus for work 11 over the ground, use control valve V4 to advancing, when V5 had carried out operation, the 2nd flow channel switching valve V13 and the 1st flow channel switching valve V12 switched earlier simultaneously or than the 1st flow channel switching valve V12.
Moreover, in this hydraulic system, each travel motor 5 about above-mentioned constitutes by oblique disc variable capacity axial motor that can height two fast speed changes, and this hydraulic system has the automatic speed reducing system of advancing, in this advances automatic speed reducing system, for example work as travel motor 5 with 2 fast state (fast states, the low capacity state) when directly advancing, when carrying out steering operation or when clearing the jumps etc., the driving force deficiency, when on travel motor 5, producing the load more than set, increase driving force in order to increase the motor capacity, it is 1 fast state (lower-speed state that travel motor 5 is slowed down from 2 fast states automatically, big capacity status).
With reference to Fig. 2 and Fig. 4 this automatic speed reducing system of advancing is described.
About each travel motor 5 as described belowly carry out rotating and drive: by making travel rod 24,25 a certain forwards, backwards square necks fall, use control valve V4 from advancing, V5 offers in a pair of motor driving loop 61 one with pressure oil via one in a pair of pressure oil supply circuit 60 and equalizing valve V18, and via another motor driving loop 61, equalizing valve V18 and another pressure oil supply circuit 60 oil extractions, by making travel rod 24,25 forwards, backwards the opposing party topple over, use control valve V4 from advancing, V5 offers in a pair of motor driving loop 61 another with pressure oil via another and equalizing valve V18 in a pair of pressure oil supply circuit 60, and via a motor driving loop 61, equalizing valve V18 and pressure oil supply circuit 60 oil extractions.
Moreover, travel motor 5 is by changing the angle of swash plate by swash plate diverter cylinder (swash plate switching actuator) 62 and switching between 1 fast state and 2 fast states, in illustrated example, when not making 62 work of swash plate diverter cylinder, travel motor 5 becomes 1 fast state, by making swash plate diverter cylinder 62 work (making the bar elongation), travel motor 5 switches to 2 fast states.
Swash plate diverter cylinder 62 is connected with cylinder control valve (actuator control valve) V19 via cylinder working loop 63, on this cylinder control valve V19, be connected with operating pressure supply circuit 64, this operating pressure supply circuit 64 optionally provides pressure oil to cylinder control valve V19 by shuttle valve V20 from the high-pressure side of a pair of motor driving loop 61, makes 62 work of swash plate diverter cylinder by the pressure oil from this operating pressure supply circuit 64.
Cylinder control valve V19 constitutes by the pilot operated transfer valve of straight movable pulley shape, can between 2 fast positions 66 and 1 fast position 67, freely switch, thereby described 2 fast positions 66 are the pressure oil from operating pressure supply circuit 64 to be offered swash plate diverter cylinder 62 via cylinder working loop 63 make travel motor 5 become the position of 2 fast states, described 1 fast position 67 is operating pressure not to be offered swash plate diverter cylinder 62 by cylinder working loop 63 is communicated with discharging loop d, travel motor 5 becomes the position of 1 fast state thus, this cylinder control valve V19 switches to 2 fast positions 66 by pilot pressure, switches to 1 fast position 67 by spring.
The pilot port of cylinder control valve V19 is connected via the delivery outlet e of guide loop 68 with the two fast transfer valve V16 that advance.
Above-mentioned guide loop 68 constitutes, from the two fast transfer valve V16 that advance to the branch midway of cylinder control valve V19, and with about the pilot port of cylinder control valve V19 of travel motor 5 be connected, and to about cylinder control valve V19 carry pilot pressure simultaneously.
The two fast transfer valve V16 that advance are made of the electromagnetic valve (transfer valve of electromagnetic mode) of straight movable pulley shape.
Be connected with the 2nd of the 4th pump P4 at this input port f that advances two fast transfer valve V16 and discharge loop 43, these two fast transfer valve V16 that advance switch to the 1 fast position 69 that guide loop 68 is communicated with discharging loop d by spring when the electromagnet demagnetization, and by the electromagnet excitation being switched to the 2 fast positions 70 that the discharge oil of the 4th pump P4 are delivered to guide loop 68.
When these two fast transfer valve V16 that advance switch to 1 fast position 69, about the cylinder control valve V19 of travel motor 5 be in 1 fast position 67, about travel motor 5 become 1 fast state respectively, when these two fast transfer valve V16 that advance switch to 2 fast positions 70, about the cylinder control valve V19 of travel motor 5 switch to 2 fast positions 66, swash plate diverter cylinder 62 work, about travel motor 5 switch to 2 fast states simultaneously.
In addition, the two fast transfer valve V16 that advance constitute by two fast operating mechanisms 71 of advancing such as button, pedal, bars and operate, in the operation signal input control device 72 from these two fast operating mechanisms 71 of advancing, send 2 fast switching command signals (excitation signal) or 1 fast switching command signal (switching signal) from 72 pairs of this control device, the two fast transfer valve V16 that advance.
On the discharge loop 29 of the discharge loop 28 of the 1st pump P1 and the 2nd pump P2, be connected with the 1st, 2 testing agencies 74,75 that constitute by pressure sensor of the pressure that detects the loop respectively, be input in the control device 72 from the detection signal of these testing agencies 74,75.
Moreover input detects the detection signal that travel rod 24,25 has been carried out the 3rd testing agency 75 of operation in control device 72.
The 3rd testing agency 75 is made of pressure sensor, connect via link circuit 77 and instruction loops 76, when travel rod 24,25 having been carried out operation, this instruction loop 76 is delivered to pilot pressure with pilot valve PV1, PV2 from advancing and advances with control valve V4, V5, thus detect to about some travel rod 24,25 a certain side forwards, backwards carried out operating (detect the 1st flow channel switching valve V12 and switched to advanced positions 34).
In the above-described configuration, operate with control valve V4, V5 advancing when detecting by the 3rd testing agency 75, and the load of travel motor 5 increases, when the 1st testing agency 73 and/or the 2nd testing agency 74 detect the above pressure of set pressure, send reduce-speed sign (erase signal) from control signal 72, the two fast transfer valve V16 that advance switch to 1 fast position 69 from 2 fast positions 70.
Promptly, even the two fast operating mechanisms 71 of advancing are being operated and are being sent 2 fast switching command signals (two fast transfer valve V16 carry out excitation to advancing) from control device 72, when travel motor 5 is advanced with 2 fast states, if to the set above load of travel motor 5 effects, then also make travel motor 51 automatically switch to 1 fast state by above-mentioned detection signal from control device 72, thus, when the load that acts on travel motor 5 increases to set when above, the motor capacity increases automatically, and the driving force of travel motor 5 increases.
Moreover, when the pressure in the discharge loop 28,29 of the 1st, 2 pump P1, P2 is reduced to less than set pressure, send restoring signal (excitation signal), the two fast transfer valve V16 that advance switch to 2 fast positions 70, but in this case, the 1st testing agency 73 and/or 74 both sides of the 2nd testing agency send restoring signal during less than set pressure at the pressure in the discharge loop 28,29 that detects the 1st, 2 pump P1, P2.
Moreover when the pressure in the discharge loop 28,29 of the 1st, 2 pump P1, P2 was reduced to less than set pressure, the restoring signal that travel motor 5 returns under the situation of 2 fast states sent with having time lag.
Promptly, in the process that travel motor 5 is advanced by two fast operating mechanisms 71, the 2 fast states that switch to of advancing, to the set above load of travel motor 5 effects, it is under the situation of 1 fast state that this travel motor 5 is slowed down automatically, make from the 1st, 2 testing agencies 73,74 to detect set above pressure fast to the response time under the situation of the two fast transfer valve V16 that advance being sent reduce-speed sign, make when the 1st, 2 pump P1, the discharge loop 28 of P2, when 29 pressure is reduced to less than set pressure, for the response time that travel motor 5 is sent the two fast transfer valve V16 that advance from the fast state of 1 fast recovering state to 2 under the situation of restoring signal slow, thereby make the two fast transfer valve V16 that advance to the recovery of 2 fast positions 70 slow (be provided with 2 quick-recovery time delay), thus, even the load of motor driving loop 61 is followed travel motor 5 to switch to big capacity status and is reduced, be not back to the low capacity state immediately yet, and can keep the big capacity status of travel motor 5, thereby can construct with respect to the stable system of volume change fluctuation that follows travel motor 5.
Moreover, when constructing the system that fluctuates stable with respect to the volume change of following travel motor 5, can constitute, make the 1st, 2 testing agencies 73,74 in the following cases detected pressures are X: promptly the 1st, 2 testing agencies 73,74 detect after the set above pressure, two fast transfer valve V16 send reduce-speed sign to advancing, it is the situation of 1 fast state that travel motor 5 is slowed down from 2 fast states automatically, make the 1st, 2 testing agencies 73,74 in the following cases detected pressures are Y: promptly the 1st, 2 pump P1, the discharge loop 28 of P2,29 pressure is reduced to less than set pressure, send restoring signal and make the situation of travel motor 5 from the fast state of 1 fast recovering state to 2, mode with X＞Y sets the 1st, 2 testing agencies 73,74 detected pressures (promptly, be set at the detected pressures height under the situations that travel motor 5 slows down automatically, the detected pressures that travel motor 5 returns under the situation of 2 fast states is low).
Moreover, also can and the control of 2 quick-recovery time delays is set and carry out being set at and being lower than the control that makes the detected pressures under the situations that travel motor 5 slows down automatically making travel motor 5 return to detected pressures under the situation of 2 fast states with these.
Moreover preferably, the setting of the detected pressures of the 1st, 2 testing agencies 73,74 and 2 quick-recoveries can freely be set respectively time delay with changing.
Moreover, in the automatic speed reducing system of advancing of present embodiment, in the process that travel motor 5 is advanced with 2 fast states to travel motor 5 effect under the situation of the load more than set, make this travel motor 5 from automatically slow down the action when being 1 fast state of 2 fast states, unlike prior art, depend on the oil temperature of pressure oil.
Moreover, in the existing automatic speed reducing system of advancing, need carry out ladder processing to the guiding valve of cylinder control valve, perhaps forming will be from the input part of the on high-tension side load detection signal input of motor driving loop, there is complicated this problem of cylinder control valve, but in the automatic speed reducing system of advancing of present embodiment, can simplify cylinder control valve V19.
In addition, in that effect has under the situation of load to travel motor 5, the travel motor 5 about can making is slowed down simultaneously automatically, can make the motion stabilization of vehicle.
In addition, in the present embodiment, above-mentioned the 1st, 2 testing agencies 73,74 are connected the upstream side of the 1st flow channel switching valve V12, but also can be arranged on the downstream of the 1st flow channel switching valve V12, do not need the 3rd testing agency 75 in this case.
Moreover the 3rd testing agency 75 also can be a detection of motion mechanism of detecting travel rod 24,25 self by limit switch etc.
In addition, in this hydraulic system, above-mentioned rotary motor 13 by can the height two fast speed changes oblique disc variable capacity axial motor constitute, for example the soil that is scooped up by scraper bowl 19 is positioned under the situation of the operation on the shelf of lorry, make panoramic table 10 revolutions while making swing arm 17 promote action, but owing to when setting the speed of gyration of panoramic table 10, pay attention to not carrying out mobility under the rotating situation of any operation, therefore in order to eliminate following unfavorable condition: promptly, speed of gyration is too fast with respect to the lifting action of swing arm 17, panoramic table 10 does not return back to target location (the lifting action and the revolution action of swing arm 17 are unmatched) unfavorable condition during swing arm 17 rises to the target location, makes rotary motor 13 be decelerated to the revolution automatic speed reducing system of lower-speed state automatically from fast state and possess when the swinging operation of swing arm 17 or big arm 18.
With reference to Fig. 2 and Fig. 5 this revolution automatic speed reducing system is described.
Moreover, rotary motor 13 is by changing the angle of swash plate by swash plate diverter cylinder (swash plate switching actuator) 82 and switching between fast state (low capacity state) and lower-speed state (big capacity status), in illustrated example, when not making 82 work of swash plate diverter cylinder, rotary motor 13 switches to fast state by spring 83, by making swash plate diverter cylinder 82 work (making the bar elongation), rotary motor 13 switches to lower-speed state.
Swash plate diverter cylinder 82 is connected via the delivery outlet g of cylinder working loop 84 with cylinder control valve (actuator control valve) V2, the input port h of this cylinder control valve V21 is connected with a pair of motor driving loop 81 via operating pressure supply circuit 85, is connected with discharging loop d at the floss hole i place of cylinder control valve V21.
Another distolateral shuttle valve 85b that is connected of the 1st oil circuit 85a that operating pressure supply circuit 85 is connected by an input port h distolateral and cylinder control valve V21, outlet side and the 1st oil circuit 85a, the 3rd oil circuit 85d that the 2nd oil circuit 85c that the input side of this shuttle valve 85b is communicated with a motor driving loop 81 and another input side that makes shuttle valve 85b are communicated with another motor driving loop 81 constitute, and this operating pressure supply circuit 85 constitutes the on high-tension side pressure oil of a pair of motor driving loop 81 is delivered to cylinder control valve V21 as the operating pressure of swash plate diverter cylinder 82.
Above-mentioned cylinder control valve V21 constitutes by the pilot operated transfer valve of straight movable pulley shape, can between high speed position 86 and low-speed position 87, freely switch, described high speed position 86 is by making cylinder working loop 84 be communicated with the position that makes rotary motor 13 become fast state with discharging loop d, described low-speed position 87 is that the pressure oil from operating pressure supply circuit 85 is delivered to cylinder working loop 84, thereby makes 82 work of swash plate diverter cylinder make rotary motor 13 become the position of lower-speed state.
Distolaterally be provided with spring 88 at one of the guiding valve of cylinder control valve V21, and a distolateral pilot port j of this guiding valve is communicated with input port h via inspection hydraulic circuit 89.
Be connected with the distolateral of instruction loop 90 at another distolateral pilot port k of the guiding valve of this cylinder control valve V21, another distolateral delivery outlet m with rotary decelerating valve V22 in this instruction loop 90 is connected.
Above-mentioned rotary decelerating valve V22 is made of the pilot operated transfer valve of straight movable pulley shape, is input to the input port n of this rotary decelerating valve V22 through unloader V15 from the pressure oil of the 4th pump P4.
This rotary decelerating valve V22 can the pressure oil that will be input to input port n offer via above-mentioned instruction loop 90 as command pressure (pilot pressure) cylinder control valve V21 supply position 91, with make instruction loop 90 and discharge loop d and be communicated with and command pressure do not offered and freely switch between the non-supply position 92 of cylinder control valve V21, this rotary decelerating valve V22 switches to by spring 93 and supplies with position 91, switches to non-supply position 92 by the pilot pressure of importing pilot port g.
Moreover, load instruction loop 94 from big arm and branch out guide loop 95, described big arm loads instruction loop 94 and carries pilot pressure to big arm with the loading operation side of control valve V6 with pilot valve PV3 from the manipulation by 26 operations of Left-Hand Drive bar, and, slave arm promotes instruction loop 96 and branches out guide loop 97, described swing arm promotes instruction loop 96 and carries pilot pressure to swing arm with the lifting fore side of control valve V8 with pilot valve PV4 from the manipulation by 27 operations of right side control stick, and these guide loops 95,97 are connected with the pilot port s of rotary decelerating valve V22.
In the above-described configuration, when control stick 26,27 does not carry out swing arm lifting operation or big arm loading operation, rotary decelerating valve V22 switches to by spring 93 and supplies with position 91, offer another distolateral pilot port k of cylinder control valve V21 via instruction loop 90 from the pressure oil of the 4th pump P4, therefore, this cylinder control valve V21 switches to high speed position 86, and cylinder working loop 84 is communicated with discharging loop d, and rotary motor 13 becomes fast state.
Therefore, rotary motor 13 uses with this fast state usually.
When making panoramic table 10 revolutions, the load of rotary motor 13 increases, when the pressure of motor driving loop 81 is elevated to set pressure when above, cylinder control valve V21 switches to low-speed position 87 by the pressure of inspection hydraulic circuit 89,82 work of swash plate diverter cylinder, rotary motor 13 switches to lower-speed state from fast state automatically.
Thus, the volume of the 3rd pump P3 can increase necessarily, can reduce the volume of the 3rd pump P3.
In addition, when control stick 26,27 being carried out swing arm lifting operation or big arm loading operation, rotary decelerating valve V22 switches to non-supply position 92 by the pilot pressure from guide loop 94,97, does not offer instruction loop 90 and gives off from the pressure oil of the 4th pump P4.
When the distolateral pilot port k of another of the guiding valve that will not offer cylinder control valve V21 from the pressure of the 4th pump P4, cylinder control valve V21 switches to low-speed position 87 by the pressure of spring 88 and inspection hydraulic circuit 89,82 work of swash plate diverter cylinder, rotary motor 13 switches to lower-speed state from fast state automatically.
Therefore, for example under the situation that panoramic table 10 revolution grades are operated swing arm 17 and panoramic table 10 simultaneously, rotary motor 13 slows down automatically, and the lifting action (speed of swing arm 17) of swing arm 17 is mated with the revolution action (speed of panoramic table 10) of panoramic table 10.
Moreover when swing arm 17 or big arm 18 not being operated, rotary motor 13 is with the fast state revolution, and the mobility of panoramic table 10 is good.
Moreover, there is not the trouble that must regulate the amount of fascinating of control stick 26,27 for the revolution action coupling of the lifting action that makes swing arm 17 and panoramic table 10.
In addition, in the present embodiment, when the loading action of the lifting action of having carried out swing arm 17 or big arm 18, rotary motor 13 is slowed down automatically, but be not limited thereto, also can constitute when dumping of the lifting action of having carried out swing arm 17 or big arm 18 moved, rotary motor 13 is slowed down automatically.
Moreover cylinder control valve V21 and rotary decelerating valve V22 can be made of electromagnetic valve, under the situation that cylinder control valve V21 is made of electromagnetic valve, do not need rotary decelerating valve V22.
[other embodiments]
Show such example in the above-described embodiment: advancing has the 1st pump P1 and two pumps of the 2nd pump P2 with pump, above-mentioned the 1st flow channel switching valve V12 constitutes, above-mentioned job position 31 make from the pressure oil of above-mentioned the 1st pump P1 with from the pressure oil interflow of above-mentioned the 2nd pump P2 and offer control valve V6, V7, the V8 that above-mentioned apparatus for work is over the ground used, and the control valve V4, the V5 that the moving device about offering independently respectively from the pressure oil of above-mentioned the 1st pump P1 and pressure oil from above-mentioned the 2nd pump P2 are used in above-mentioned advanced positions 34.
But, for example also can be that advancing with pump is the formation beyond above-mentioned such as.Advancing with pump is under one the situation, the 1st flow channel switching valve V12 constitute can be when non-advancing will from the pressure oil with pump of advancing offer control valve V6, V7 that apparatus for work over the ground uses, V8 job position 31, and will advance pressure oil with pump when advancing from above line and offer about the advanced positions 34 of moving device the control valve V4, the V5 that use between switch.
Claims (5)
1. the hydraulic system of an excavator has:
Advance with pump (P1, P2), pressure oil is offered the control valve (V4, V5) that moving device is used;
Revolution offers the control valve (V1) that panoramic table is used with pump (P3) with pressure oil;
The 1st flow channel switching valve (V12), can between job position (31) and advanced positions (34), switch, described job position (31) is will enter the position that pressure oil with pump offers the control valve (V6, V7, V8) that apparatus for work over the ground uses from above line when non-advancing, and described advanced positions (34) is the position of the control valve (V4, V5) used of the moving device about will advancing pressure oil with pump and offer from above line when advancing;
The 2nd flow channel switching valve (V13), can and supply with between the position (40) in non-supply position (39) and switch, described non-supply position (39) is will not offer the position of the control valve (V6, V7, V8) that above-mentioned apparatus for work over the ground uses from above-mentioned revolution with the pressure oil of pump (P3), described supply position (40) is to offer the position of the control valve (V6, V7, V8) that apparatus for work over the ground uses with the pressure oil of pump (P3) from above-mentioned revolution
In the process of operating at the control valve that above-mentioned apparatus for work is over the ground used (V6, V7, V8), the control valve (V4, V5) that the above line motion device is used is operated, make above-mentioned the 1st flow channel switching valve (V12) when job position (31) switches to advanced positions (34), above-mentioned the 2nd flow channel switching valve (V13) and above-mentioned the 1st flow channel switching valve (V12) switch to from non-supply position (39) earlier simultaneously or than above-mentioned the 1st flow channel switching valve (V12) and supply with position (40).
2. the hydraulic system of excavator as claimed in claim 1 is characterized in that, above-mentioned advancing has the 1st pump (P1) and these two pumps of the 2nd pump (P2) with pump,
Above-mentioned the 1st flow channel switching valve (V12) constitutes, above-mentioned job position (31) make from the pressure oil of above-mentioned the 1st pump (P1) with from the pressure oil interflow of above-mentioned the 2nd pump (P2) and offer the control valve (V6, V7, V8) that above-mentioned apparatus for work is over the ground used, and the control valve (V4, V5) that the moving device about offering independently of one another from the pressure oil of above-mentioned the 1st pump (P1) and pressure oil from above-mentioned the 2nd pump (P2) is used in above-mentioned advanced positions (34).
3. the hydraulic system of excavator as claimed in claim 1 is characterized in that, has:
Advance and detect loop (54), when the control valve that the above line motion device is used (V4, V5) when having carried out operation, this is advanced and detects loop (54) pilot pressure is offered above-mentioned the 1st flow channel switching valve (V12) so that the 1st flow channel switching valve (V12) is switched to above-mentioned advanced positions (34);
With stream switching circuit (41), in the process of operating at the control valve that above-mentioned apparatus for work is over the ground used (V6, V7, V8), the control valve (V4, V5) that the above line motion device is used is when having carried out operation, this stream switching circuit (41) can offer pilot pressure above-mentioned the 2nd flow channel switching valve (V13), so that being switched to, the 2nd flow channel switching valve (V13) supplies with position (40)
Above-mentioned stream switching circuit (41) is provided with stream switch operating valve (V17), this stream switch operating valve (V17) constitutes, at the off-position (58) that pilot pressure is not offered above-mentioned the 2nd flow channel switching valve (V13) and pilot pressure is offered between the operating position (59) of above-mentioned the 2nd flow channel switching valve (V13) and freely switch, and by switching to operating position (59) from the above-mentioned pilot pressure that detects loop (54) of advancing.
4. the hydraulic system of excavator as claimed in claim 2 is characterized in that, has:
Advance and detect loop (54), when the control valve that the above line motion device is used (V4, V5) when having carried out operation, this is advanced and detects loop (54) pilot pressure is offered above-mentioned the 1st flow channel switching valve (V12) so that the 1st flow channel switching valve (V12) is switched to above-mentioned advanced positions (34);
With stream switching circuit (41), in the process of operating at the control valve that above-mentioned apparatus for work is over the ground used (V6, V7, V8), the control valve (V4, V5) that the above line motion device is used is when having carried out operation, this stream switching circuit (41) can offer pilot pressure above-mentioned the 2nd flow channel switching valve (V13), so that being switched to, the 2nd flow channel switching valve (V13) supplies with position (40)
Above-mentioned stream switching circuit (41) is provided with stream switch operating valve (V17), this stream switch operating valve (V17) constitutes, at the off-position (58) that pilot pressure is not offered above-mentioned the 2nd flow channel switching valve (V13) and pilot pressure is offered between the operating position (59) of above-mentioned the 2nd flow channel switching valve (V13) and freely switch, and by switching to operating position (59) from the above-mentioned pilot pressure that detects loop (54) of advancing.
5. the hydraulic system of an excavator has:
Advance and detect loop (54), when the control valve that moving device is used (V4, V5) when having carried out operation, this is advanced and detects loop (54) pilot pressure is offered the 1st flow channel switching valve (V12), above-mentioned the 1st flow channel switching valve (V12) is switched to the advanced positions (34) that pressure oil is offered the control valve (V4, V5) that the above line motion device uses;
With stream switching circuit (41), in the process of operating at the control valve (V6, V7, V8) that apparatus for work is over the ground used, the control valve (V4, V5) that the above line motion device is used is when having carried out operation, this stream switching circuit (41) can offer pilot pressure above-mentioned the 2nd flow channel switching valve (V13), above-mentioned the 2nd flow channel switching valve (V13) is switched to the supply position (40) that pressure oil is offered the control valve (V6, V7, V8) that above-mentioned apparatus for work over the ground uses
Above-mentioned stream switching circuit (41) is provided with stream switch operating valve (V17), this stream switch operating valve (V17) constitutes, at the off-position (58) that pilot pressure is not offered above-mentioned the 2nd flow channel switching valve (V13) and pilot pressure is offered between the operating position (59) of above-mentioned the 2nd flow channel switching valve (V13) and freely switch, and by switching to operating position (59) from the above-mentioned pilot pressure that detects loop (54) of advancing.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006266592A JP4302724B2 (en) | 2006-09-29 | 2006-09-29 | Backhoe hydraulic system |
| JP2006-266592 | 2006-09-29 | ||
| JP2006266592 | 2006-09-29 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101158167A true CN101158167A (en) | 2008-04-09 |
| CN101158167B CN101158167B (en) | 2011-08-10 |
Family
ID=38926327
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2007101532299A Active CN101158167B (en) | 2006-09-29 | 2007-09-29 | Backhoe hydraulic system |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US7743611B2 (en) |
| EP (1) | EP1905903B1 (en) |
| JP (1) | JP4302724B2 (en) |
| CN (1) | CN101158167B (en) |
| DE (1) | DE602007004787D1 (en) |
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| CN104947734A (en) * | 2014-03-28 | 2015-09-30 | 株式会社久保田 | Hydraulic system for working machine |
| CN105492698A (en) * | 2013-08-22 | 2016-04-13 | 洋马株式会社 | Industrial vehicle |
| CN105008724B (en) * | 2013-05-30 | 2017-03-08 | 日立建机株式会社 | The fluid pressure drive device of engineering machinery |
| CN109072957A (en) * | 2016-12-22 | 2018-12-21 | 株式会社久保田 | Working rig |
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| KR100939802B1 (en) * | 2007-09-17 | 2010-02-02 | 볼보 컨스트럭션 이키프먼트 홀딩 스웨덴 에이비 | Hydraulic circuit for heavy equipment |
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| JP7069620B2 (en) * | 2017-09-29 | 2022-05-18 | コベルコ建機株式会社 | Hydraulic system |
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Also Published As
| Publication number | Publication date |
|---|---|
| US7743611B2 (en) | 2010-06-29 |
| EP1905903A1 (en) | 2008-04-02 |
| EP1905903B1 (en) | 2010-02-17 |
| JP4302724B2 (en) | 2009-07-29 |
| JP2008082521A (en) | 2008-04-10 |
| DE602007004787D1 (en) | 2010-04-01 |
| CN101158167B (en) | 2011-08-10 |
| US20080078174A1 (en) | 2008-04-03 |
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